CHAUFFERETTE PORTABLE

PORTABLE HEATER

Abrégé français

Cette invention concerne une chaufferette portable comprenant une chambre de combustion, une enveloppe extérieure disposée autour de cette chambre et servant à la contenir, le fond de l'enveloppe étant espacé du fond de cette chambre pour définir un espace libre vertical entre les deux, le diamètre de l'enveloppe étant supérieur au diamètre de cette chambre de manière à définir entre les deux un espace libre circulaire renfermant un organe vertical de canalisation du flux d'air favorisant un écoulement convectif servant d'isolation thermique entre ledit organe et l'enveloppe, l'organe de canalisation étant espacé de la paroi de la chambre de combustion et orienté de façon à définir canal d'écoulement convectif convergent d'air chaud dirigé vers le haut et à l'extérieur de l'enveloppe. L'enveloppe comporte près de sa base des orifices d'admission d'air tout comme l'organe de canalisation d'air pour que le flux d'air convectif passe en partie dans le canal d'écoulement précité du côté vide thermoisolant vers la bouche de sortie et en partie dans le passage d'air menant à la sortie d'air chaud en partie haute, les orifices susmentionnées ayant pour fonction de créer une aspiration d'air ambiant à l'intérieur de l'enveloppe et dans l'espace libre y ménagé pour une circulation d'air continue. Un couvercle amovible est prévu pour fermer le haut de l'appareil en ajustement serré, ledit couvercle étant équipé d'une poignée calorifugée pour assurer la portabilité de l'ensemble.

Abrégé anglais

A portable heater comprising a fire chamber vessel, an outer enclosure containeraround the vessel for retaining it, the container bottom being spaced below the vessel
bottom to define a vertical space therebetween, the container breadth being sufficiently
greater than the vessel breadth to cause the container peripheral wall and the vessel
peripheral wall to define a circumferential space therebetween, an upright air flow control
member in the circumferential space spaced from the container peripheral wall to create
convection air-flow, heat-insulating space between the control member and container
peripheral wall, and having an upper discharge outlet; the control member being spaced
from the vessel peripheral wall and oriented to create an upwardly convergent convection
heat exchange air flow conduit between the flow control member and the vessel peripheral
wall, and an upper heat outlet between said control member and said vessel for discharge
of heated air; air flow inlet openings in the container adjacent the container bottom, and
air flow inlet orifices past said air flow control member adjacent the container bottom
from the circumferential space to the conduit, whereby convection air flow will occur
partially up through the heat insulating space to the discharge outlet and partially up
through the air flow conduit to the upper heat outlet, to draw ambient air through the
container openings and partially through the orifices for continued air circulation. A
closure cover is configured to removably interfit with the vessel open top, and has a
thermally insulated handle for portability.
-10-

Revendications

The embodiments of the invention in which an exclusive property or privilege is
claimed are defined as follows.
1. A portable heater comprising:
a fire chamber vessel having a peripheral wall, a bottom, a depth, a breadth andan open top;
an outer enclosure container around said vessel for retaining said vessel;
said container having a bottom, a peripheral wall, an open top, and a breadth;
said container bottom being spaced below said vessel bottom to define a verticalspace therebetween;
said container breadth being sufficiently greater than said vessel breadth to cause
said container peripheral wall and said vessel peripheral wall to define a circumferential
space therebetween;
mounting fasteners between said vessel and said container, retaining said vesseland said container in spaced relationship to each other;
an upright air flow control member in said circumferential space, said control
member being spaced from said container peripheral wall to create convection air-flow,
heat-insulating space between said control member and said container peripheral wall, and
having an upper discharge outlet;
said control member being spaced from said vessel peripheral wall and oriented to
create an upwardly convergent, convection heat exchange air flow conduit between said
flow control member and said vessel peripheral wall, and an upper heat outlet between
said control member and said vessel for discharge of heated air;
air flow inlet openings in said container adjacent said container bottom; and
air flow inlet orifice means for air flow past said air flow control member,
adjacent said container bottom, from said circumferential space to said conduit whereby
convection air flow will occur partially up through said heat insulating space and through
said discharge outlet, and partially up through said upwardly convergent air flow conduit
and through said upper heat outlet, to draw ambient air through said container openings
and partially through said orifice means for continued air circulation.
2. The portable heater in claim 1 including a closure cover for said vessel configured
to removably interfit with said vessel open top.
--5--

3. The portable heater in claim 2 including interfitting connectors on said vessel open
top and said closure cover.
4. The portable heater in claim 3 wherein said interfitting connectors comprise a
plurality of spaced slots on one of said open top and said closure cover, and a plurality of
interfitting studs on the other of said open top and said closure cover, cooperative with
said slots.
5. The portable heater in claim 3 including a carrying handle on said closure cover,
and thermal insulation between said handle and said closure cover.
6. The portable heater in claim 1 wherein said mounting fasteners are at spaced
locations around said vessel and container.
7. The portable heater in claim 6 wherein said fasteners also retain said flow control
member in position.
8. The portable heater in claim 1 wherein said openings are in said container
peripheral wall.
9. A portable heater comprising:
a fire chamber vessel having a peripheral wall, a bottom, a depth, a breadth andan open top;
an outer enclosure container around said vessel;
said container having a bottom, a peripheral wall, an open top, and a breadth;
said container bottom being spaced below said vessel bottom;
said container breadth being sufficiently greater than said vessel breadth to cause
said container peripheral wall and said vessel peripheral wall to define a circumferential
space therebetween;
fastener means between said vessel and said container for retaining said vessel and
said container in spaced relationship;
an upright air flow control member in said circumferential space, said control
--6--

member being spaced from said container peripheral wall to create a thermal insulating
space, and spaced from said vessel peripheral wall and oriented to create a heat exchange
air flow conduit between said flow control member and said vessel peripheral wall, and
having an upper heat outlet from said heat exchange air flow conduit for discharge of
heated air from said heat exchange air flow conduit;
air flow inlet means to said heat exchange air flow conduit for air flow up through
said heat exchange air flow conduit and said upper heat outlet; and
a closure cover for said vessel configured to removably interfit with said vessel
open top, and a carrying handle on said cover thermally insulated from said cover.
10. The portable heater in claim 9 including interfitting connectors on said vessel open
top and said closure cover, whereby said heater can be carried by said handle.
11. The portable heater in claim 10 wherein said interfitting connectors comprise a
plurality of spaced slots on one of said open top and said closure cover, and a plurality of
interfitting studs on the other of said open top and said closure cover, cooperative with
said slots to secure said cover in place on said vessel.
12. A portable heater comprising:
a fire chamber vessel having a peripheral wall, a bottom, a depth, a breadth andan open top;
an outer enclosure container around said vessel;
said container having a bottom, a peripheral wall, an open top, and a breadth;
said container bottom being spaced below said vessel bottom;
said container breadth being sufficiently greater than said vessel breadth to cause
said container peripheral wall and said vessel peripheral wall to define a circumferential
space therebetween;
fastener means between said vessel and said container for retaining said vessel and
said container in spaced relationship;
an upright air flow control member in said circumferential space, said control
member being spaced from said container peripheral wall to create a thermal insulating
space, and spaced from said vessel peripheral wall and oriented to create a heat exchange
air flow conduit between said flow control member and said vessel peripheral wall, and
-7-

having an upper heat outlet from said heat exchange air flow conduit for discharge of
heated air from said heat exchange air flow conduit;
air flow inlet means to said heat exchange air flow conduit for air flow up through
said heat exchange air flow conduit and said upper heat outlet;
said air flow control member and said container peripheral wall defining a
convection air flow, thermal insulating space therebetween, a top discharge outlet from
said space, and bottom air inlet orifices in said container to said space, whereby cooling
air can flow by convection through said air flow inlet means, said space and said
discharge outlet; and
a closure cover and a carrying handle on said closure cover, and thermal insulation
between said handle and said closure cover.
13. A portable heater comprising:
a fire chamber vessel having a peripheral wall, a bottom, a depth, a breadth andan open top;
an outer enclosure container around said vessel;
said container having a bottom, a peripheral wall, an open top, and a breadth;
said container bottom being spaced below said vessel bottom;
said container breadth being sufficiently greater than said vessel breadth to cause
said container peripheral wall and said vessel peripheral wall to define a circumferential
space therebetween;
fastener means between said vessel and said container for retaining said vessel and
said container in spaced relationship;
an upright air flow control member in said circumferential space, said control
member being spaced from said container peripheral wall to create a thermal insulating
space, and spaced from said vessel peripheral wall and oriented to create a heat exchange
air flow conduit between said flow control member and said vessel peripheral wall, and
having an upper heat outlet from said heat exchange air flow conduit for discharge of
heated air from said heat exchange air flow conduit;
air flow inlet means to said heat exchange air flow conduit for air flow up through
said heat exchange air flow conduit and said upper heat outlet;
said air flow control member and said container peripheral wall defining a
convection air flow, thermal insulating space therebetween, a top discharge outlet from
-8-

said space, and bottom air inlet orifices in said container to said space, whereby cooling
air can flow by convection through said air flow inlet means, said space and said
discharge outlet; and
said outer container bottom has thermal insulation.
14. The portable heater in claim 13 wherein said container bottom has a pair of
vertically spaced panels and said thermal insulation comprises an air space between said
panels.
15. The portable heater in claim 13 wherein said thermal insulation comprises a solid
layer of insulation material.
-9-

Description

220 1 522
....~
PORTABLE HEATER
BACKGROUND OF THE INVENTION
This invention relates to portable heaters of the type that burn charcoal, for
fishing, camping, hllnting shelters, boating, spectator sports and the like.
A variety of wood or charcoal burning stoves and heaters have been previously
proposed over the last several decades, certain ones of which have been provided with
handles for portability. As far as is known, however, these prior heaters, when
operational, have had the characteristic of being very hot to the touch. Therefore, these
heaters have not only been a potential hazard for burns, especially for children, but also
not truly portable, or at best very difficult and hazardous to move from place to place,
even if theoretically possible.
SUMMARY OF THE INVENTION
An object of this invention is to provide a portable heater of the charcoal burning
type, which is not only efficient in operation, creating convection flow of hot air, but
which is also cool and safe to the touch, even when operational. The heater provides a
quietly generated, inexpensive heat. It can be readily transported to the woods or other
place of use, in hand or even in a vehicle, safely and reliably. It is efficient when
ignitecl, operational on a small amount of fuel, draws unheated air and ejects it in
stream as heated air, yet without moving devices such as fans. The device can bemanufactured at a reasonable price so as to be readily affordable.
The novel heater has a unique triple wall construction formed in such a manner
that it creates convection flow past the fire chamber vessel, the air flow being caused to
occur in a manner that both keeps the exterior surface cool, and optimizes heat exchange
from the fire chamber. The heater has the fire chamber vessel spaced from the
surrounding enclosure container, both around the periphery and at the bottom, there being
a flow control member or divider in the space between the two, causing upward air flow
between the divider and the outer container for thermal insulation, and air flow between
the divider and the fire chamber vessel wall for heat transfer from the heater as well as a
thermal insulation effect. This divider has a frustoconical configuration, creating an
upwardly convergent heat exchange air flow conduit between the flow control member
and the fire chamber vessel wall, for optimi7ing upward draft along the surface of the fire
chamber for optimum output. The outer container has air inlet openings adjacent the
bottom of the chamber. Air flow is also allowed at the adjacent bottom of the divider

220 1 522
.
member, preferably through orifices. Hence, a controlled, desired portion of the air
entering the outer container flows upwardly through the thermal insulating space between
the flow control member and the outer wall, and the other portion of the entering air
flows between the flow control member and the fire chamber vessel wall.
These and other objects, advantages and features of the invention will become
apparent upon studying the following specification in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is an elevational view of the novel heater with the cover and handle shown
removed from the remainder of the assembly;
Fig. 2 is a top plan view of the heater in Fig. 1, with the cover and handle
removed;
Fig. 3 is a side elevational, sectional view of the novel assembly, with the cover
and handle shown extended above the assembly; and
Fig. 4 is a sectional view taken on plane IV-IV of Fig. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now specifically to the drawings, the assembly 10 in Fig. 1 comprises a
generally cylindrical outer enclosure container 12 having a bottom 12',, a peripheral wall,
an open top and a breadth or diameter. Suspended within this outer container is a fire
chamber vessel 16 which preferably is also cylindrical in cross section, and has a
peripheral wall, a bottom 16', a depth which is less than the depth of outer container 12,
and an open top. Preferably the upper rim of vessel 16 is generally coplanar with the
upper rim of container 12, and has an upwardly outwardly flared top 16". Extending
upwardly-inwardly from the flared top 16" are a plurality of rivet type pins or studs 18
generally normal to the upwardly outwardly extending top 16".
Vessel bottom 16' is spaced upwardly from container bottom 12'. Container
bottom 12' has thermal insulation which may be in the form of an air space 20 between a
pair of vertically spaced horizontal panels 12' and 22, preferably supported at the
periphery of bottom 12' by a diagonally dowllwaLdly outwardly oriented flange asdepicted in Fig. 3. Alternatively, this air space 20 may be substituted by or
supplemented by a layer of thermal insulation 21 such as solid polymeric foam materials
of conventional type, or the equivalent.
The peripheral wall of vessel 16 is spaced inwardly from the peripheral wall of
container 12 to define a circumferential space therebetween. Vessel 16 is suspended in

2201522
~.
this condition from container 12 by fasteners such as a plurality of threaded bolts or studs
24 extending through the two spaced peripheral walls, and secured in position as by
cooperative nuts 26 or the equivalent. Preferably, these threaded fasteners 24 also rest on
the upper edge of an upright air flow control member 14 which is located in the
5 circumferential space between container 12 and vessel 16. The air flow control member
is preferably frustoconically configured, having its smaller diameter end oriented
upwardly and its larger diameter end oriented downwardly, the latter resting upon and
being held in place at the outer periphery of container bottom 12'. Although fasteners 24
could conceivably extend through control member 14, this is not necessary since member
1014 can be retained securely beneath fasteners 24 and above bottom 12'. Control member
14 thereby divides the circumferential space into an outer heat insulating space 30
between the inner peripheral wall of container 12 and control member 14, and an inner
heat exchange conduit 32 between control member 14 and the outer peripheral wall of
vessel 16.
15Adjacent the bottom of container 12, through the peripheral wall thereof as
depicted, is a plurality of air inlet openings 13. Also, adjacent the bottom of control
member 14 is a plurality of air inlet orifices 15. At the top of space 30 is an open
discharge outlet. At the top of conduit 32 is an upper heat outlet. Hence, cool ambient
air entering openings 13 will partially flow up between divider 14 and the inner peripheral
20 wall of container 12 by connection to the upper discharge outlet for thermally in~ ting
the outside of the container to keep it cool. Simultaneously, a desired portion of the same
cool ambient air flowing through openings 13 will flow by convection through orifices 15
and upwardly along the outer surface of heated vessel 16, i.e., through conduit 32
between the outer peripheral wall of vessel 16 and the inner surface of control member
25 14, to be heated and discharged through the upper heat discharge outlet. The discharged
air from both space 30 and conduit 32 will mix and flow out between the upper rim of
vessel 16 and the upper rim of container 12, into the ambient air. Air flow control
member 14, by its upwardly inwardly sloped configuration, causes conduit 32 to be
constricted gradually toward the top of vessel 16 such that ambient air flowing by
30 convection past the peripheral wall of vessel 16 increases in velocity while being forced
closer to vessel 16, to scrub the surface of the vessel for efficient heat transfer from the
fire chamber. The venturi type discharge will also drawn air up through space 30.
The open top of vessel 16 can be closed by a cover 40 which is generally
--3--

220 1 522
horizontal in configuration but with an upwardly-outwardly flared rim to match the
configuration of the upwardly-outwardly flared rim 16" of vessel 16. Cover 40 is shown
to include horizontally elongated, arcuate slots 42 having one end enlarged at 42'
sufficiently to receive the heads of rivets 18. A grab handle 46 is mounted to the center
of cover 40 by an insulator block 48. By placing cover 40 on vessel 16 such that the
heads of rivets 18 pass through enlarged openings 42', and then rotating the cover using
handle 46, the vessel can be closed to largely curtail further combustion air from entering
the fire chamber while totally cont:~ining the hot charcoal fuel from spillage, for safe
transportation thereof.
In use, charcoal is placed in the bottom of fire chamber vessel 16 and ignited.
Once the charcoal is burning adequately, air in conduit 32 will heat, rise and discharge.
Air in space 30 will also heat to a lower temperature to rise and discharge. This
convection flow will cause ambient air to be drawn through openings 13, partially flowing
up through space 30, and partially flowing through orifices 15 and up conduit 32, to the
upper outlets. It has been determined by experimentation that air flow through space 30
keeps the outer container 12 cool to the touch so as to not be dangerous, while the flow
through conduit 32 is heated efficiently. The two air flows mix above the upper rim of
control member 14, and exit into the ambient air for effective heating of the space around
the heater. If it is desired to dampen heat output, cover 40 is placed on the open top of
vessel 16 to limit entry of oxygen flow. If it is desired to move the heater from place to
place, the cover is rotated to lock the slots and pins 42 and 18 together. Experimentation
has shown that it can be safely carried from place to place by hand, or taken by vehicle,
without complications. The heat generated from the charcoal will continue for a
considerable time after the cover is placed in position, due to residual combustion air
rem~ining in the vessel.
The bottom air space 20, either with or without or substituted by a layer of solid
insulation such as a foam polymer, causes the bottom of the container to remain cool so
as to not endanger a person or the surface on which it is placed.
Conceivably those skilled in this field might consider certain additional features or
modifications to be made to accommodate certain uses. The invention is not intended to
be limited to the specific preferred embodiment set forth, but only by the scope of the
appended claims and the reasonably equivalent structures to those defined therein.
-4 -

Dessin représentatif